Measurement of relatively small pulse width has become increasingly important in various applications. These applications include, for example, determining exact timing characterization, securing reliability of on-chip sensors, determining critical path delay time or hold time on-chip, measuring rising and falling slew rate on-chip, determining on-chip SRAM access time, detecting static and dynamic noise margins, etc. In some semiconductor chips, delay caused by circuits is relatively small, such as in the order of 10 picoseconds. As a result, measurement of timing parameters poses a challenge. In some methods, automatic testing equipment (ATE) is employed for pulse width measurement. However, limitations on ATE make it difficult to measure the pulse width of a relatively small pulse with desirable resolution and desirable accuracy in digital circuits.